∫e^x / (1 + e^x) dx = ?
Question 1
Q1. ∫e^x / (1 + e^x) dx = ?
Answer: ln|1 + e^x| + C
Explanation: Using substitution u = 1 + e^x, du/dx = e^x, hence ∫e^x / (1 + e^x) dx = ∫du/u = ln|u| + C.